A member of the California Department of Fish and Wildlife prepares to rescue a pelican covered in oil Wednesday on the beach. A broken pipeline spewed oil into the ocean Tuesday.

GOLETA, Calif. — More than 6,000 gallons of oil had been raked, skimmed and vacuumed from a spill that stretched across 9 miles of California coast in a cleanup effort that is now going 24 hours a day.

Investigators took stock of the scope of the spill on Wednesday a day after the pipeline break, finding that up to 105,000 gallons may have leaked out, and up to a fifth of that amount — 21,000 gallons — reached the sea, according to estimates.

Federal regulators were investigating the leak as workers in protective suits raked and shoveled the black sludge off the beaches, and boats towed booms into place to corral the two slicks off the Santa Barbara coast.

The chief executive of the company that runs the pipeline, Plains All American Pipeline, was at the site Wednesday and apologized for it.

“We deeply, deeply regret that this incident has occurred at all,” Chairman and CEO Greg L. Armstrong said at a news conference.

Armstrong said the company had received permission to continue cleanup operations around the clock and vowed that it “will remain here until everything has been restored to normal.”

Crude was flowing through the pipe at 54,600 gallons an hour at the time of the leak Tuesday, the company said. Company officials didn’t say how long it leaked before it was discovered and shut down, or discuss the rate at which oil escaped.

Federal regulators from the Department of Transportation, which oversees oil pipeline safety, investigated the leak’s cause, the pipe’s condition and the potential regulatory violations.

The 24-inch pipe built in 1991 had no previous problems and was thoroughly inspected in 2012, according to Plains. The pipe underwent similar tests about two weeks ago, though the results had not been analyzed yet.

The Los Angeles Times reported that the company accumulated 175 safety and maintenance infractions since 2006, according to federal records. The infractions involved pump failure, equipment malfunction, pipeline corrosion and operator error.

The paper said a Plains Pipeline spokesman did not immediately respond to a request for comment about its regulatory record.

There was no estimate on the cost of the cleanup or how long it might take.

A combination of soiled beaches and pungent stench of petroleum caused state parks officials to close Refugio State Beach and El Capitan State Beach, both popular campgrounds west of Santa Barbara, over the Memorial Day weekend.

The state Department of Fish and Wildlife closed fishing and shellfish harvesting for a mile east and west of Refugio beach and it deployed booms to protect the nesting and foraging habitat of the snowy plover and the least tern, both endangered shore birds.